Friday, June 27, 2014

The Scoop on Some Old Poop

Neandertals ate their veggies, their feces reveal

Scientists excavating an archaeological site in southern Spain have
finally gotten the real poop on Neandertals, finding that the Caveman
Diet for these quintessential carnivores included substantial helpings
of vegetables. Using the oldest published samples of human fecal matter,
archaeologists have found the first direct evidence that Neandertals in
Europe cooked and ate plants about 50,000 years ago.

The extinct Neandertals, who lived from about 230,000 to 30,000 years ago, have long been portrayed as uber-carnivores—humans
at the top of the food chain who ate mostly meat to fuel their
revved-up metabolisms in order to survive in the frigid climes of
northern Europe and Asia. This image was based on evidence from
butchered meat bones and hunting tools at archaeological sites, as well
as from studies of carbon, nitrogen, and other chemicals in the
fossilized teeth of Neandertals, which can reveal their diets. But a
recent study of starches in the plaque of Neandertal teeth indicated
that Neandertals in modern-day Iraq and Belgium ate grasses, tubers, and other plants,
and that they also cooked barley grains in Iraq. This view of
Neandertals gathering plants and cooking barley porridge challenged the
old view that our burly cousins went extinct because they depended too
much on meat, whereas versatile modern humans could survive on a broader
range of plant and animal foods. But it was still unclear whether
vegetables made up a significant part of the European Neandertal diet.

Now, at an open-air archaeological site called El Salt in Alicante,
Spain, researchers have gathered fossilized feces in the sediment where
Neandertals lived at different times between 40,000 and 60,000 years
ago, before modern humans arrived in the region. By applying a powerful
method that was developed for detecting fecal matter in drinking water,
geoarchaeologist Ainara Sistiaga of the University of La Laguna in
Tenerife and geobiologist Roger Summons of the Massachusetts Institute
of Technology in Cambridge have detected the biological
signature, or biomarkers, of meat and plants in the sediments
containing fossilized feces from five different places at El Salt.
Specifically, the team was able to detect the chemical byproducts
created by bacteria in the gut in the digestion of cholesterol from
meat, as well as sterols and stanols, which are lipids in plants that
are similar to cholesterol. The tests revealed that the poop “clearly”
contained high proportions of cholesterol and coprostanol from eating
meat, but it also included significant plant sterols that “unambiguously
record the ingestion of plants,” the researchers report today in PLOS ONE.